Self-piloted rotary drill bit



Aug. 19, 1952 O, Inl-"Pps 2,607,562

SELF-PILOTED ROTARY DRILL BIT Fild March 19; 1951' y Znventor Gtorneg Patented ug. 19, 195.2

UNITED STATES PjiAiTlllNV'.y OFFICE 2,607,562 i j Y SELF-PILOTED ROTARY DRILL BIT- ()rville Phipps, Adams County, Inear Denver, Colo.

Application March 19, 1951, Serial No. 216,308

Claims.

This invention relates to bits rotatable with and as the free end termination of a drill string to develop bores in and through earth strata, and has as an object to provide an improved such bit characterized by high penetrative eiiciency.

A further object of the invention is to provide an improved removable and replaceable drill bit of multi-wing, stepped type operatively conservative of power and time.

A further object of the invention is to provide an improved rotary drill bit operable for the simultaneous development of coaxial cuts of progressively greater radii determinative of a straight `bore of the desired diameter.

A further object of the invention is to provide a stepped type rotary drill bit that is facile and economical of production in any desired range of sizes, adaptable at the time of production to variations suited to particular operating problemsand conditions, susceptible of convenient rehabilitation in the field, and durable throughout a long life of practical use. l

With the foregoing and other objects in view, my invention consists in the construction, arrangement, and combination of elements hereinafter set forth, pointed out in my claims, and illustrated by the accompanying drawing, in which- Figure 1 is an end elevation of a typical embodiment of the invention. Figure 2 is a side elevation of the improvement according to Figure 1. Figure 3 is an end view of the illustrated embodiment, partly in section, taken substantially on the indicated line 3-3 of Figure 2. Figure 4 is a longitudinal section through the illustrated embodiment taken substantially on the indicated line 4--4 of Figure 1.

In the construction of the improved bit, as shown, the bit body, formed of tractable metal, preferably by forging, is constituted with a rightcylindrical base or butt portion I0, an integral, frusto-conical portion Il coaxial with the base portion I0 and taperingv thence to a working or free end of reduced diameter, and an integral, coaxial boss I2 of relatively reduced diameter outstanding from the base I0 end remote from the portion I I in a working of its exterior surface, as by means of threads, adapting said boss to function as means for removably and replaceably associating the bit body with, as a coaxial free end extension of, and for rotation about its axis by a conventional power-rotatable drill string with the reduced end or tip of the body portion l I directed away from the said string; it being desirable, in accord with customary practice, that the boss I2 operate to abut the end 'of the Adrill string against ends thereof to constitute a passage for the W of cooling and scavenging iluid from and as conventionally supplied through the associated drill string, and the end of said bore opening through the reduced end of the portion II is internally threaded for purposes which will hereinafter appear.

Characteristic of the improvement, and giving eifect to certain principles of the invention, a plurality of like wings I4 is formed integrally with and to outstand in a uniform angular spacing laterally from the bit body in a number, two, three, four, or more, and particular relation with the bit body suited to given operating conditions; three such wings being shown in the drawings. Each of the wings I4 has a smooth, plane face I5 leading in the direction of bit rotation and radial of thebit body at the lesser or-free end of the latter remote from the boss I2, said face I5 being inclined at any appropriate small angle selected at the time of the bit manufacture relative to a plane through the bit axis to dispose the end of the wing adjacent the boss I2 in rotationally trailing relation with the wing end remote from said boss, therebyto impress a positive operational rake on the bit wings. the trailing face of each wing I4 is preferably tangential with the frusto-conical bit body portion Il exterior surface, and the edge, or free side margin, of each wing I4 is stepped, in three or more stages, from a minimum projection radially and outwardly of the bit body at the lesser end of the portion II to a maximum radial and outward projection, determinative of ultimate b ore diameter, adjacent the mergence of said portion II with the base I0, whence the said'wing edge inclines inwardly and toward the boss I2 to merge into said base; the free edge margin of each of the so-constituted wing steps being parallel to the bit body axis.

The tractable nature of the metal from which the bit elements I0, II, I2, and I4 are comprised enhances the facility and economy of bit manufacture but is ill-suited to withstand the abrasive and wear effects of bit operation, hence the step corners and adjacent leading face areas of the Wings, being the cutting elements of the assembly, are armored and protected by blocks I6 of -suitable hard, tough, abrasion-resistant, alloy material, such as tungsten-carbide, recessrseated and secured, as bybrazing or welding, in

and in flush relation with each wing leading face n in an end-overlapped, stepped interrelation appropriate to register and align outer side margins and exposed end corners of said blocks with the corresponding margins and end corners of the wing steps; said blocks IB being generally rectangular in plan and section, of a size in plan to longitudinally interengage and laterally overlap, and of an adequate stress-resistant thickness less than the wing thickness'at their mountings thereon, whereby to provide a backing of tractable material in supporting relation with each block.

Inner margins and the trailing faces of the blocks I8 are closely conformed with the corresponding recess elements and are firmly and permanently adhered thereto by known and readily-available techniques. With the blocks I6 mounted in the arrangement and relationships shown and described, the side margins of the blocks are ground into Asmooth mergence r.with the adjacent wing step margins, ex-posed l-end corners of said Ablocks land their backing stepfniaterial are laterallybeveled fas maya-be desired, and said -corners are groundrto'advance leadingedges of said corners longitudinali-y of the bit :assembly beyond their trailing'edges-in a bi-telof appropriate `vordesired pitch; vma-intenanceof the block Working sidemargins and endicorners ineicientfunctioning condition being a simple grinding operal'fiori convenient of performance -in the eld Vand of repetition until the block width is substantially exhausted.

In the '-anglebetween adjacent `wings M, and hence in immediate yleading relation with the armoredworking face of each wing, holes l1 are formed in any desired'nuinber. ltwo or more, through the body Aportion H tocommunicate with the bore' l andk provide uid Voutflow from said'bore to and across the blockV 1S faces, withv cooling and scavenging eifectthereon; said holes .preferably .being appropriately inclined relative to `the borefaxisto lfacilitate and suitablydirect such: outflow. y i 'i' Completing tliedrifllloitiassembly for practical operatioirfa separate pilot'b-it'luiiit :is yremovably 1 Vandreplaceably associated with` andto; proj ect-axially roin--theend of the biti-bo'cly remotefromthe boss lsaid pilotbitunit being` formed'on'and cylndricalstem Hl cooperable with `the internal threads at the outer end of 'the bore 'I3 'inobilarly spacedfro'm a second diametric plane perpendicularj to `sai"cl"r`irst plane, whereby 'to 'define a slot extending diametrically of the head l 9 between saidfingers and opening outwardly axially thereof. The fingers 2i) are `arranged to dispose theirplane'faces inthe direction of bit rotation, and a block 2l of alloy material, conveniently the 'same as that from which the blocks I6 are formed,

isv edge-seated in and to ll the diametric slot between said lfingers and to extend at each end be- 'ycnd the side margins thereof with its free, or outer,sedge ,disposed diametrically and 4projected axially relative :to the -head I9. Thus, the side margins, exposed faces, and end edges of the fingers 26 are armored and protected by the block 2l alloy material which functions as the advanced cutting element of the assembly during bit rotation and develops a pilot bore of small diameter effective to guide the bit in its enlargement of the pilot bore and tofacilitate the Work of the blocks i6, the working margins of said block 2l, both side and end, being ground to merge with their backing material in such bite inclination as may be appropriate. Exterior corners and ad- -jacent surface areas of the fingers 2l] immediately lbeneath the outer endsof the block 2| undesirably abrade and Wear away during operation of the bit when constituted solely from the tractable material of the head I9, hence it is expedient to armor and protect said corners by means of strips 2l of wear-resistant alloy material recessseated and secured in the outer end corners of the nger 5251 lplane faces to close between the base-of leach .finger and -the vinner margin of the corresponding block 2li vend.4 A bore `22 axially-,of the Ystein .i8 Vis branched vWithin lthe -head I9 -to openthrough the base ofeachiinger-ZQ adjacent Athe leadingfacearea'of the vblock 2 I, .thereby to provide o-w-of cooling andscavengingiluid across the block working `faces and about the block working edges. l i y It is to be noted that the arrangement-of Wings ,i4 and' pilot vlbit `fingers 20 results vin an unusually large space'through which Vfluidacarrying cuttings may uprise withelficient-scavenging effectvtorobviate any clogging or sticking of vthe-drill --due to poor scavenging; that the provision of Ythe alloy7 blocks Vas the Lsole'cutting*elements of the bitiin an arrangement permitting rehabilitation of their cutting Yedges in the -Veld conduces to `along and operatively Ie'fiicierit :bit life; and `that the stepped'rela'tionship of the block 2l and `I65side Vmargins is productive of-a progressive borefenlargement conducive to straight lbore development and low Vpower requirements.

vSince changes, variationafand modifications in theform, construction, andarrangement of lthe Aelements shown and describedmay Vbehad without departing vfrom thefspiritof my invention,I wish 5to be understood `as `being ulimited solely :by .the scope of the appended-claims, rather than by `any details o'fltheillustrative showing and foregoing description. f

I claim asmy-invention: n .1. A bit ofthe characterrdescribed comprising abondy of "tractable-metal formed with a-cylin dricalbase portion and Vva, coaxial truste-conical -portion tapering from said base portion toa `free 'working end offreduced-diameter, means *on the freeend of said base portion removably and .replaceably engageable with Yandv tofmount 4said body as a simultaneously-rotatable terminal Aextension on'a drillstring, integr-a1 wings outstanding laterally from andina uniformity'of angular spacing about-*said body anda mergenceof jtheir appropriate ends intofthe-body'base portion, .planesurfaees approximately radial of the body ata slightlongi-tudinal inclinationeto the body ,axisfdefining the Wing faces -leading in the direction of -body rotation 4with' their 'ends adjacent the body free end advanced IinftheA direction i of rotationrelative to their 'opposite f ends, angular steps similarly interrupting -free side-margins of said Vwin-gs `to define successive annular cutting zones perpendicularv to `tine-- body `axis and-of-progressvlygreater diameters awayl from the body free'endblocks of 'abrasiveresistant .alloy materalrecess-'seated and se'curedin the leading face area of each wing step in marginal registration therewith, means for the circulation of fluid placeably outstanding coaxially from the free end of said body.

2. The organization according to claim 1, wherein the wing surfaces trailing in the direction of body rotation merge into and tangentially with the -body surface for the development of a Wing root buttressed against the stresses incident to bit operation.

3. The organization according to claim 1, wherein the said angular steps are right angular with their side margins paralleling the body axis and their end margins in planes perpendicular to the saidv axis.

4. The organization according, to claim 1, wherein the blocks of alloy material are generally rectangular in a relative size and mounted interrelation to overlap the outer side margin of a lesser diameter step block on the end margin of the next greater diameter step block and outwardly beyond the inner side margin of said latter block.

5. The organization according to claim 1,

6 wherein said pilot bit is constituted with a body of tractable metal, is furnished with a block of alloy material slot-seated diametrically of the body free end in an axially-directed, cutting exposure of its outer edge and a projection of its ends effective to overlap the cutting orbit of the adjacent wing alloy blocks, and is bored Ifor the circulation of uid from the associated bit body across and in advance of its alloy block working elements leading in the direction of bit rotation.

ORVILLE PHIPPS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,096,134 4Sims May 12, 1914 1,547,459 Staiord et al July 28, 1925 1,847,302 Emmons Mar. 1, 1932 1,887,373 Emmons et al Nov. 8, 1932 1,902,513 Meutsch Mar. 21, 1933 2,504,978 Hennings Apr. 25, 1950 2,578,593 Phipps Dec. 1l, 1951 

